Hydraulic control system



' March 4, 1958 '0. B. ENYEART ET AL 2,825,307

HYDRAULIC CONTROL SYSTEM Filed Jan. 19', 1956 FIG. 2

.l 84 as 52 62 70 v 12 l2 J 64 48 '4 FIG. 4

ENTORS no NAGLE v. GUYSCHING DUANE B. ENYEART AGENT therein.

Un ted Ps sn Sidney, Ohio, a corporation of Ohio Application January 19,1956, Serial No. 560,183 2' Claims. '61. in -41 This invention relatesto means for controlling hydraulic motors which, due to the particularconstruction, have a definite limit of motion. In this class of motorsprincipally fall piston and cylinder motors, and paddle motors whereinone or more paddles move between one or more abutment vanes. Inaccordance with thisinvention this class of motors is improved byproviding means by which they may move to definite positionsintermediate the end positions created by their inherent structure.

Therefore it is an object of this invention to provide means wherebymotors which have discontinuous motion may be stopped intermediate theirend positions.

It is another object to provide means whereby such motors may be stoppedaccurately and positively intermediate their end positions.

It is another object ,to provide means whereby such motors may bestoppedat any one selected position of a plurality of different positions.

It is another object to provide means to provide such stopping controlin an, economical manner.

Other objects and advantages will become apparent on consideration ofthe following specification and the attached drawings in which Figure 1is a partial sectional elevation. of a rotary motor taken generallyalong the line. 11 ,of Figure 2,

Figure 2 is a sectional view of across the axis of the motor of Figure 1taken along the line 2--2 of Figure 1,

Figure 3 is a partial elevation of the embodiment of Figure 1 takenalong the line 3-3 of Figure l, and

Figure 4 is a partial cross sectional view of a difierent embodimentwherein the motor with which the invention is employed is of the linearmotion type.

Referring now to Figure 1, a rotary motor is shown This motor has aframe mounting member carrying a generally circular motor frame 12 andwithin the motor frame 12 is a rotary member 14 which carries an outputgear 16. Embracing the motor frame 12 is a cylindrical valving member'18 which may be manually moved by means of a plate .20 which is securedto the member 18 by means of screws 22 and is keyed to a shaft 24 bymeans of a key 26. On the other end of the shaft 24 is'a knob 28 whichis keyed thereto for manually rotating the shaft 24 .and the cylindricalmem ber 18 which rotates therewith.

As is best seen in Figure 2 the output member 14 carries a vane 30 whichrotates within the confines of the stationary member 12 in an almostannular space therein. Member 12 carries thereon an abutment member 32which provides walls to limit the motion of the vane 30 and through themeans of the vane 30 and abutment 32 two spaces 34 and 36 are defiend.It can be readily seen that if fluid under pressure is permitted to flowinto one of the spaces, for example 34, and space 36 is permitted to beconnected to a drain, the vane 30 will have a pressure dilferentialthereacross and the output member 14 will move in a clockwise 2,825,307Patented Man 4, i958 2 direction as viewed in Figure 2. Motion of theoutput member 14 will turn gear 16 which is secured thereto byappropriate means such as screws 38. Clearance between the motor frame12 and the vane 30 as well as between the output member or rotor 14 andthe abutment 32 is kept at a minimum to minimize leakage.

According to applicants invention, motor frame 12 has a plurality ofholes or ports 40, 42 44, 46, 48, 50, 52, 54, 56, 58', and 60communicating between its interior and it s exterior. These holes arespaced apart and are related to the width of the vane 30 so that thevane 30 substantially closes at'least two of the holes. The'cylindricalmember 18 acts as a valving member and contains two holes 62 and 64which are adapted to line up with two of the holes in the member 12,which holes are spaced apart approximately the width of the, vane 39 asis mentioned above. The holes 62 and 64 are permitted to drain fluid tothe sump. It can be seen that manual motion of knob 28 causescylindrical valving member. 18 to rotate and valve different pairs ofholes 40 to 60 to drain.

, The abutment 32 contains interdrilling which provides fluid inlets 66and 68. Inlet 66 is connected to line 70 (see Figure 3) and inlet 68 isconnected to line 72. A pump 74draws fluid from a sump 76 through line78 and discharges it under pressure to lines 80 and 82. Lines 80 and 82are respectively connected to lines 70 and 72 through fluid resistances84 and 86. Hydraulic oil is preferably used as an operating fluid for itacts as a lubricant as well as a power medium. However, gas, 'water, orother liquid could be used by providing suitable clearances so norubbing occurs or by the provision of carbon or special metal in thewearing areas to prevent galling. I

In the illustration of Figures 1 through 3 the motor is shown as havingone vane and one abutment. As is well known in the art, twodiametrically opposed vanes and two diametrically opposed abutments maybe used .to

double the torque with the same fluid pressure at the,

expense of total motion. In this case the cylindrical valving member 13would be provided with two diametrically opposed pairs of holes toprovide openings to drain adjacent both sides of both vanes when therotor is in its desired position. Fluid would be supplied throughresistances to both sides of both abutments. I

The pump 74 supplies the operating fluid under pressure to lines 80 and82, and the pressure may be limited to a safe value by means of a reliefvalve or by'using a pressure compensated variable delivery pump. Theresistances 84 and 86 are. provided to act as flow dividers so that whenone or the other of lines 70 or 72 is open to drain the pump pressuredoes not fall off appreciably but fluid under pressure is supplied tothe other side of movable vane member 30 to cause motion. Of courseseparate pumps could be used to supply lines .70 and 72 or other knownflow dividing means could be. used.

It can be seen from the description of the device of Figures 1 through3-that as the pump 74 discharges fluid under pressure into lines 80 and82 it is conveyed through resistances 84 and 86 into spaces .36 and34through ports 66 and 68. If the knob 28 is turned to cause the ports 62and 64 to lie over the ports 54 and 56 it can be seen that the space 36will be opened to drain through port 56 and port 64. At the same timethe fluid entering through port 68 will be under pressure to cause aforce to act on the face of vane 30 and this force will turn the outputmember 14 in a clockwise direction as seen in Figure 2 until the vane 36covers both ports 54 and 56. In this position the pressure in space 36will rise for it is no longer open to drain and the vane 30 will stop.Preferably, the vane 30 does not ber 14 is very accurate. If the angularposition of vane 30 is incorrect to the slightest extent, one drain willbe at least slightly opened and the pressure on that side of the vane 36will fall due to flow through and consequent pressure drop in resistance84 or 86. A correcting force results to restore the vane 30 to thecorrect position. If the knob 28 is turned the other way so that ports42 and 44 communicate todrain through ports 62 and 6 1, it can be seenthat the space 34 is open to drain and fluid under pressure enteringthrough port 66 will move the vane 30 until it covers both ports 42 and44. By moving the cylindrical valving member 18 over any pair of portsin the motor frame 12 the' vane 30 is moved by power to cover that pairof ports. Of course,-if the vane 30 is made the same width as one of theports in motor frame 12, only one of the ports need be opened to "drain.Thus the vane 38, output member 14, and gear 16, seek their newposition. Gear 16 can be used to drive any device such as a selectorvalve where accurate positioning in a plurality of different positionsis desired.

The embodiment of Figure t is a reciprocating fluid motor having acylinder 88 and a piston 90 therein. The piston divides the cylinderinto spaces 92 and 94 in cooperation with the end walls of cylinder 88and connected to the piston'90 is a piston rod 96. A pump 98 draws fluidfrom a sump 1th) through a suction line 162 and the pump 93 delivers itunder pressure through two fluid resistances 194 and 106. Resistance 164is connected by means of line 198 to a port in the end of the cylinderto discharge into space 92 and resistance 106 discharges into a line 110which in turn is connected into space 94 in the other end of thecylinder 88. The cylinder is securely mounted in a stationary fashion bymeans of the lines 108 and 110 or by any other suitable structuralmeans. The cylinder 88 has a plurality of holes 112 therein and theholes are spaced apart such a distance that at least two of them aresubstantially cov ered by the piston 90 at the same time. The holes 112serve as ports for porting to drain. Embracing the cylinder 88 is acylindrical valving member or sleeve 114 which contains ports 116 and118 for porting pairs of the holes 112 to drain. The ports 116 and 118are spaced in such a manner that they open selected pairs of ports 112to drain.

It can be seen that if the sleeve 114 is moved to port the leftmost pairof ports 112 to drain through ports 116 and 118, that the space 92 willbe open to drain but fluid under pressure will flow through resistance1% and line 110 to the space 94 thereby causing the piston 9 and its rod96 to move leftward until the piston covers the pair of drained ports.Similarly, the cylindrical valving member 114 can be moved to align withports 116 and 118 with any pair of ports 112 to open them to drain.Fluid pressure on the other side of piston 90 causes the piston to moveto cover both of the drained ports 112.. Thus it can be seen that thismotor can move to any one of a plurality of selected positions foraccurate positioning of the piston rod 96 and the appropriate mechanismattached thereto. Again, if the piston is of such width as to cover onlyone port 112, then only one port need be opened to drain to causepositioning.

While valving has been described as being done by ported valving members18 and 114, it is clear that valving could also be done by anyappropriately op erating valves. For example, if an electricalpositioning signal is available, it might be desirable to use solenoidoperated valves. These motors have been described in particularity withrespect to input and output members, but it can be seen that the membersdescribed as output members herein can be secured to the frame and theother member be used as an output member.

This invention is capable of a number of embodiments and thus it isdesired that the scope of the invention be defined by the appendedclaims.

What we claim 18? 1. In a unitary fluid pressure, actuated motor andmotor control valve structure, a frame, walls defining an annular spacein said frame, an abutment on said frame extending into said annularspace, a driven member arranged to oscillate around a given axis, a vaneon said driven member extending into said annular space, fluid pressuresupply means for supplying fluid to said space on each side of saidabutment, a plurality of ports in said frame, at least one of said portsbeing away from said abutment, a valving member embracing said frame andcovering said ports and having valving ports therein, said valvingmember being actuatable coaxiaily with said driven member to open atleast one of said ports from said space, whereby upon supplying fluid tosaid space on each side of said abutment said vane moves to cover saidopen port.

2. In a unitary fluid pressure actuated motor and control valvestructure, a main frame .for supporting the motor and control valve,said frame having cylindrical walls arranged around a centerlinedefining an annular space in said frame, an abutment in said frameextending into said annular space, a driven member arranged to rotatearound a given axis which corresponds to the center line of saidcylindrical walls, a vane on said driven member extending into saidannular space, said vane and said abutment dividing said annular spaceinto first and second spaces, fluid pressure supply means for supplyingfluid under pressure into each of said spaces, a plurality ofsubstantially radial ports in said frame extending from said annularspace to the outside of said frame, at least one of said ports beingaway from said abutment, a valving member embracing said frame andarranged to cover said ports and having at least one valving porttherein, said valving member being rotatable, in the same plane and onthe same axis as said driven member to correspond to the desiredposition of said driven memher to open at least one of saidsubstantially radial ports, whereby upon supplying fluid to said firstand second space on the sides of said abutment said driven member iscaused to rotate to cover said open port so that it seeks the sameangular position as a valving member.

References Cited in the file of this patent UNITED STATES PATENTS1,484,030 Kitchen Feb. 19, 1924 2,219,955 Smitt Oct. 29, 1940 2,398,997Berry et a1. Apr. 23, 1946 2,481,426 Hull Sept. 6, 1949 2,703,149 NelsonMar. 1, 1955

